Especially when winding heavy weight packages at the high rates of speed which is required for efficiency of operation in many modern textile producing facilities, it is desirable to provide a rotatable spindle which is otherwise fixed in position and onto which a surface driven tube or other package support is secured. The tube is rotated by means such as a drive roll contacting the tube surface directly and thereafter the strandular material wound thereon to thus wind an advancing strand of yarn or the like into a package. Suitable strand traversing means are also provided to distribute the strand from end to end of the package support and the previous strand layers of the package built thereon. Such traversing and drive means are conventionally mounted on some common means which permits their relative movement away from the package supporting spindle as the package wound thereon builds in diameter. In this manner the need to support a member which increasingly assumes a greater weight as the package winds with the necessary rigidity to prevent undesirable vibrational movement and the like is eliminated.
However, such a configuration requires that the means for carrying the traversing and drive means ie. the carriage means, be exceedingly sensitive to pressure applied thereto by the progressive winding of the strand upon the package support as the package progressively grows in diameter. Several devices presently available and which use pneumatic or mechanical linkages to support such carriage means have been found to introduce irregularities into the package produced by slight but abrupt changes in winding tension in turn caused by slight inconsistent upward movements in the carriage means. Thus in systems utilizing a pneumatic carriage with a supporting piston, pressure within the piston must build up to a finite point to overcome the inherent friction of its cylinder wall contact and when that point is reached the carriage jumps ahead a distance determined by the progressive package building action. Although such sequential pressure buildup and release produces very slight movements in the upward travel of the carriage, the movements are nevertheless abrupt and thus undesirable. Similar undesirable abrupt movements are introduced by the mechanical systems presently known.
Through emperical determinations, the present applicant has further found that it is desirable when winding packages of the type under consideration, that the introduction of a slight lessening of the driving force between the drive means and package as the package builds in diameter produces desirable package characteristics.
The present invention is thus directed to a winding apparatus which accomplishes the above indicated objectives while eliminating the above indicated shortcomings of prior art devices by the provision of a winding apparatus including a fixed position rotatable spindle adapted to receive a package support thereon and rotatable therewith. Strand traversing means for guiding the strand onto the support and drive means including a rotating drum for contacting the surface of the support and thereafter the strand surface as the package is progressively built to rotate the support and package mounted thereon is further included. Both the strand traversing and drive means are mounted on a carriage supported for free vertical movement towards and away from the independently supported fixed position spindle. An initial weight to at least partially counterbalance the combined weight of the carriage and the strand traversing and drive means mounted thereon is suspended from a common frame by means of a cable and pulley system so that pressure transmitted to the drive means as the package progressively builds on its support is freely and without variation transmitted smoothly to the carriage so as to enable a smooth unimpeded upon travel thereof. Such initial weight means places a minimum constant driving force on the package which is augmented by a differential pressure means which initially places an additive driving force on the package and thereafter gradually reduces such additive driving force as the package progressively builds.
With the foregoing in mind, it is a principal object of the present invention to provide a new and improved winding apparatus capable of winding an advancing strand at high speeds into heavy weight packages without undesirable pressure variations being introduced in the resultant package.
Another object of the present invention is to provide a winding apparatus including a counterweight means which permits smooth unhesitant upward movement of a traverse and drive means supporting carriage.
Still another object of the present invention is to provide a winding apparatus which enables the pressure or relative tightness of the package formed thereby to be varied during the building thereof by the incorporation of a differential pressure means for gradually reducing the driving force on said package as the package builds.
Other objects of the invention will appear in the following descriptive portions of the subject specification.